Question

4 resistor of 20 ohm are connected in the series and the combination is connected to 20v emf device the potential difference acrosany one resistor will be ????

Answer 1

Answer:5V

Explanation:Total R= 80ohms

So current flowing through the circuit will be V/R=1/4 A

Since the resistors are in series, the current remains see.

So, V=IR= 20×1/4=5 V

Answer 2

Solution:

let, r1, r2 ,r3 and r4 be the four resistors connected in the series.

V be the emf device connected in the series with the four resistors.

I be the current flowing through the circuit.

R be the total resistance or equivalent resistance.

here, given in the question that

r1 = r2 = r3 = r4 = 20ohm.

V = 20v

since, r1, r2, r3 and r4 are connected in the series.

so, the equivalent resistance will be

R = r1+r2+r3+r4

R = 20+20+20+20

R = 80ohm.

now, current in the circuit

I = V/R

I = 20/80

I = 0.25A

and potential difference(v1) across r1 will be

v1 = Ir1

v1 = 0.25*20

v1 = 5v.

therefore, the potential difference across any one resistor will be 5v.